# CalBMIv5.py
y_or_n = input("是否退出程序（y/n）？")
while y_or_n != 'y':
    try:
        height, weight = eval(input("请输入身高(米)和体重(公斤)[逗号隔开]: "))
        bmi = weight / pow(height, 2)
        print("BMI 数值为：{:.2f}".format(bmi))
        who, nat = "", ""
        if bmi < 18.5:
            who, nat = "偏瘦", "偏瘦"
        elif 18.5 <= bmi < 24:
            who, nat = "正常", "正常"
        elif 24 <= bmi < 25:
            who, nat = "正常", "偏胖"
        elif 25 <= bmi < 28:
            who, nat = "偏胖", "偏胖"
        elif 28 <= bmi < 30:
            who, nat = "偏胖", "肥胖"
        else:
            who, nat = "肥胖", "肥胖"
        print("BMI 指标为:国际'{0}', 国内'{1}'".format(who, nat))
    except SyntaxError:
        print("请输入西文的标点！")
    except Exception:
        print("程序异常！")
    finally:
        print()  # 输出空行
        y_or_n = input("是否退出程序（y/n）？")
else:
    print("已退出程序")
